Wheel suspension is a very important component of motorcycle performance. Good suspension provides superior handling, improved balance and improved comfort. In motorcycle systems, the rear wheel is typically a separate suspension system and has a different suspension design than the front wheel. A variety of the current rear wheel motorcycle suspension systems commonly mount the rear wheel on a swing arm that rotates about a fixed axis. The motion control of the swing arm is generally a shock absorber and spring system that controls the rotation of the swing arm. In motorcycle embodiments, this has proved useful to some degree.
U.S. Pat. No. 3,948,543 to Macdonald, et al. granted Apr. 6, 1976 was an early patent in presenting a rear wheel shock absorber translating substantially upward impact forces into a substantially horizontal force. U.S. Pat. No. 5,279,383 to Gustafsson provides a composite leaf spring suspension mounted under the motorcycle limiting the angular rotation of the pivot arm. U.S. Pat. No. 4,653,604 to de Cortanze shows a complicated three arm lever rotatably mounted on a lever axle. U.S. Pat. No. 4,515,236 to Kanamori provides a five-pivot axis system for maintaining control of the angular rotation of the pivot arm.
In off-road racing, fallen logs and large boulders can prove to be an obstacle to even a seasoned rider. Clearing the front wheel over an obstacle is generally fairly straightforward as the rider can shift weight. The rear wheel however can strike an obstacle and pull the rider off the off-road motorcycle or cause loss of balance. The rear wheel collision can also damage the off-road motorcycle. Off-road four-wheel vehicles also have the same problem with rear wheel collision. Riders need an improved suspension system for a motorcycle rear wheel to provide an enhanced ride on extremely rugged surfaces and have enhanced rear wheel collision recovery.